1. Field of the Invention
The invention generally relates to a light-emitting device and a repairing method thereof. More particularly, the invention relates to a light-emitting device capable of being repaired easily and the repairing method thereof.
2. Description of Related Art
An Organic Light-Emitting Diode (OLED) is a self-emissive type light-emitting device used in displays or light sources. When the OLED is used for illumination, a capability to illuminate a large area is usually required. As shown in FIG. 1A, in order to provide a sufficient illumination area, manufacturers usually configure a plurality of OLEDs in a parallel to form a light-emitting device. When a terminal of the OLED is connected to a V+ voltage while another terminal is connected to GND, the OLED simultaneously emits light. However, as shown in FIG. 1B, when a cathode and an anode of one of the OLEDs are shorted, the driving current is conducted to GND due to the short circuit between the cathode and the anode, causing a lighting failure of the OLED.
As shown in FIG. 2A, instead of configuring a plurality of OLEDs in parallel, some manufacturers configure the OLEDs in series to form a light-emitting device that provides sufficient illumination area. As shown in FIG. 2B, when a cathode and an anode of one of the LEDs are shorted, the driving current can still be transmitted to other normally functioning OLEDs. Therefore, while the abnormal OLED fails to emit light, other normally functioning OLEDs are still lit. Nevertheless, as the number of serially connected OLEDs increases, a driving voltage required also increases. As shown in FIG. 2C, if the driving voltage required to drive a single OLED is V+, the driving voltage required to drive n OLEDs is n times V+.
Accordingly, the light-emitting devices depicted in FIGS. 1A and 2A have unsolved problems. How to improve the failed OLEDs without a drastic increase in driving voltage is one of the research issues for manufacturers.